In recent years, electric vehicles powered by electric energy have been put into practical use to reduce carbon dioxide emissions and achieve efficient utilization of energy. Electric vehicles, however, have a short cruising range of approximately 100 km to 200 km when they are in full charge as the energy density of batteries for electric vehicles is lower than that of gasoline, and the cruising range further decreases through power consumption by electrical loads such as an air conditioner.
To solve this problem, technology for promoting energy saving in the electrical loads in the electric vehicles to reduce power consumption during traveling and to thereby extend the cruising range has been proposed.
As such technology, Patent Document 1 discloses a vehicle power management system that calculates a market price of electricity (an electricity price) from a power supply-demand situation (total power consumption of electrical loads, power generation cost, and storage cost) of a traveling vehicle, and notifies various electrical loads installed in the vehicle of the electricity price, for example.
In the vehicle power management system disclosed in Patent Document 1, the electrical loads installed in the vehicle can indirectly grasp the power supply-demand situation of the vehicle from the electricity price, and, by setting proper electricity purchasing ability in the electrical loads, energy-saving operation of the electrical loads can be achieved in accordance with the power supply-demand situation of the traveling vehicle, for example, by transitioning to operation in a power save mode when the electricity price is high.